Cars have been outfitted with biometric readers like fingerprint scanners and voice recognition for years, but chances are you've never seen an anti-theft system quite like this: we now have car seat that can actually identify you by the subtle curves of your hindparts.

The unusual security device was designed by a team of Japanese engineers from the Advanced Institute of Industrial Technology in Tokyo. According to Wired's Mark Brown:

The driver's seat is kitted out with 360 different pressure sensors, which can detect how far they've been depressed from a range of 0 to 256. This 3D picture of your bum is sent to a nearby laptop and becomes a personalised identifier.

Next time someone plonks their keister into the car the system analyses the curves, dips, ridges and bumps of the behind. The car won't go into gear if it ain't your rear. The motor won't run if that isn't your bum. The car won't be going fast, if it doesn't detect your... Ahem.

The engineers' seat has reportedly achieved a 98% recognition rate in preliminary trials. According to business newspaper Nikkei, the researchers will seek to commercialize the "highly reliable anti-theft system" within three years.

Will booty-based security measures become the next big thing in the automotive industry? Maybe. But we're definitely excited by the possibility of a future where stealing a car could require the use of a prosthetic posterior. [TechCrunch via Wired]Top image via ShutterstockImage of seat and sensor readings via Wired